Isn't the draft pick money from a completely separate pool? I know it all counts against the cap, but I think only a certain percentage for the cap is automatically allotted to draft picks by the CBA.
I could be wrong....

The rookie cap is a subset of the overall cap. The cap for all teams is the same with variations that occur due to some incentive pay being charged from one year to another and incidents like Tim Couch.

The rookie cap is set by the league and is individual to each team based on their draft. It is part of the overall cap.

The Packers were unlikely to use the maximum(we don't know for sure yet at the time of this post because of Rogers). Nevertheless they had the room.

Tampa Bay was unprepared and is cutting veterans this week to to make signing room. The Packers were prepared and will have room for signing additional players in case of injured reserve etc.

If they have money near the end of the year they will extend a player to ensure they spend near the maximum of the cap as possible. This was done last year with Tony Fisher.

Overall the Packers are in good shape with the players they have. The problem has been that with 12% dead money the long term view of the team this is a down year. One player and the dead cap account for almost 25% of the cap.

Next year there will be a lot of money available but there are many players to sign as well. Approximately 50% of the team and 50% of the cap. Next offseason will be more exciting than this one.